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Electronics Engineering
Electronics Engineering is a branch of engineering that deals with practical applications of electronic components, devices, systems, or equipment. Electronics are devices that operate on low voltage sources, as in electron tubes, transistors, integrated circuits, and printed circuit boards and use electricity as part of its driving force.
24,372 Questions
Why does adding more resistance result in less current?
As the name implies, resistance resists current. In the mathematical formula, where E is electromotive force (voltage):- I = E/R If you increase the value of R (resistance), then the value of I (current) decreases.
Can 1700 mAh battery replace 250 mAh battery?
In general, no. The charger is designed for a specific battery profile, and it might not be able to properly charge and/or monitor the amount of charge if you put in a different battery.
How long will it take a 1 μF capacitor to completely discharge through a 47 kΩ resistor?
forever. the discharge curve of an RC circuit is exponential and the closer it gets to discharged the slower it discharges. this is true for all values of capacitors and resistors.
What are the advantages of moving coil instrument?
Advantages are:- high sensitivity, uniform scale, very effective and reliable eddy current danping well shelded from any stray magnetic field. Disadvantages are:- very expensive, only suitable for direct current and voltages.
What are the advantages using 3D Radar over 2D Radar?
The three Dimensional maps created a revolution in the field of navigation and medical and also in the engineering field. The advantage of 3D maps are that it can give the idea of all the dimensions and hence better designs can be created by looking at the 3d maps and the conventional maps were not that much informative compared to 3D maps are
What is Class B push-pull amplifier?
When we get amplifier output current for 180 degrees of input. then it's called B class amplifier.
In a push pull class B amplifier one of the two power transistors or other amplifying elements handles the positive half of the waveform and the other element handles the negative half of the waveform.
In practice, push pull audio amplifiers are usually class AB; each power transistor handles slightly more than 180 degrees of input. This minimizes distortion (crossover distortion) when one of the two transistors ceases output and the other takes over.
a relay switch can be used to control one voltage from another(e.g. 24 volt controlling a 120v circuit), or controlling multiple functions and circuits from one voltage switch or location. advantages to relays are that the size of conductor can be greatly reduced with a lower voltage(cost and ease of installation) and consumer convienience(one switch for 100 lights or one photocell controlling an entire parking lots lighting even with a rating of 15 amps)
Compare high level modulation and low level modulation?
IN LOW LEVEL MODULATION THE MODULATING SIGNAL IS APPLIED NEARER THE CARRIER OSCILLATOR N IN HGH LEVEL MODULATION MODULATING SIGNAL IS APPLIED AT OUTPUT OF FINAL POWER AMPLIFIER OR FAR FROM CARRIER OSCILLATOR... IN OTHER WORDS :::: IN HAIGH LEVEL MODULATION THE AF SIGNAL IS APPLIED TO COLLECTOR OR PLATE AS THEIR RESPECTIVE DEVICES..... N IN LOW LEVEL MODULATION AF SIGNAL IS APPLIED AT BASE OR GRID IN TRANSISTOR AND TUBES RESPECTIVILY IN LOW LEVEL MODULATION THE MODULATING SIGNAL IS APPLIED NEARER THE CARRIER OSCILLATOR N IN HGH LEVEL MODULATION MODULATING SIGNAL IS APPLIED AT OUTPUT OF FINAL POWER AMPLIFIER OR FAR FROM CARRIER OSCILLATOR... IN OTHER WORDS :::: IN HAIGH LEVEL MODULATION THE AF SIGNAL IS APPLIED TO COLLECTOR OR PLATE AS THEIR RESPECTIVE DEVICES..... N IN LOW LEVEL MODULATION AF SIGNAL IS APPLIED AT BASE OR GRID IN TRANSISTOR AND TUBES RESPECTIVILY
What colour is the solid copper?
- bare copper wire is copper orange color.
- tinned copper wire is silvery color.
- enamel coated copper magnet wire can come in any color, depending on enamel.
- plastic coated copper hookup wire can come in any color, depending on plastic.
copper wire for household wiring is color coded using plastic coating:
- black - hot 120 VAC
- white - neutral 0 V current return
- green - ground 0 V safety return (no current normally)
- red - hot 120 VAC, opposite phase from black for use in 240 VAC hookups
- etc.
copper wiring for industrial 3-phase power has additional colors, which I won't visit here.
copper wire for electronic use follows an entirely different color code:
- red - positive DC power
- black - DC return
- green - negative DC power, or signal if no negative power
- other colors - signals
don't confuse color codes!
The first DC motor was made by a British scientist William Sturgeon in the year of 1832. The motor he made was the first motor capable of turning machinery.
What are the advantages of optical fiber over waveguide?
much wider bandwidth. Ie, many more signals can be run over the same cable.
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Optical transmission has several advantages over copper wire:
- optical fibre's high bandwidth means that a lot more data can be transmitted faster.
A pair of copper wires (which is what most houses in urban areas use for the initial point of access to the Internet can transmit two telephone calls simultaneously, while a single optical fibre can transmit over 80,000; - glass is cheaper and lighter than copper;
- optical fibre is unaffected by electro-magnetic interference, and so is ideal in electrically "noisy" environments, eg where there is high voltage equipment nearby;
- no electrical current is transmitted down a fibre (glass is a good insulator), so it is suitable in hazardous environments where electrical discharge would dangerous;
- as transmission technology continues to improve, higher and higher bandwidths are possible over the same optical fibre links without having to replace the cables.
What are the main parts of a DC servo motor?
Motor inside and outside movement and non movement material
Why Silicon is used widely as a semiconducting material?
Silicon is abundant in nature as SiO2(sand).
Getting the Si from SiO2 is comparatively easier than other semiconductors like Ge.
And Silicon is a better conductor at room temperature.
valence electron in germanium are in fourth shell whereas on silicon valence electron is in third shell.
germanium valence electron are at higher energy level than silicon .hence germanium valence electron will need smaller amount of energy to escape form the atom due to this germanium more number of electron pair than silicon . hence leakage current is more.
this property makes germanium more unstable at high temperature.
What is the unit of electron current?
Electron current flow is measured in coulombs per second, which is known as amperes.
A coulomb is about 6.242 × 1018 electrons.
What is the advantages and disadvantages of varactor diode?
is basically an electrically controlled variable capacitor
no moving parts need a monitored voltage source to hold the value
temperature sensitive Si based dont work over 100C
variable capacitors in the mechanical adjusted variety work with higher voltages arent voltage spike sensitive and are far more rugged are in picofarad to micro farad range can handle many kilowatts set and forget dont need controls to maintain capacitance arent temperature sensitive can be motor driven for electric control
A: Initially the construction of an FET closely resemble the double diffused bipolar epitaxial transistor Both begins with an n+ substrate n- forming a 4 layer structure. another distinguishing feature is the electrical bonding of the upper most n+ diffusion [source] however with this bonding a parasitic diode in parallel cathode drain to source fortunatelly by virtue the polarity operation is unaffected. All in all FET have higher power, higher voltage rating practically no thermal runaway and a greatly inhibited secondary breakdown characteristics
What isDifference between ordinary rectifier and precision rectifier?
A simple rectifier circuit uses a diode and there is a turn ON voltage for the diode. The input voltage has to exceed the turn ON voltage (0.6V for ordinary Si diode) before rectification is achieved.
A precision rectifier is an active circuit using an opamp and a diode in the feedback loop. This overcomes the turn-on "knee" voltage.
The op amp reduces the turn-on voltage of a diode in its feedback loop by a factor equal to the open-loop gain of the op amp. For practical op amp gains this reduces the forward voltage to a fraction of a mV, thus giving a "precision" or near ideal diode characteristic for the rectifier function.
Why does an ammeter have a low resistance while a voltmeter has high resistance?
I am going to assume that you mean low "resistance" in an open circuit test and are performing this with a multimeter. An ammeter works by place a very small amount of resistance in series with a circuit and then measuring the Voltage drop across the resistance. The Voltage is directly proportional to the current as given in ohms law: E = I x R If you are measuring the resistance through the ammeter it will have a very low resistance and impedance.
The question is invalid.
Volts is a unit of electrical potential in fundamental units of joules per coulomb. Watts is a unit of (electrical) power in fundamental units of joules per second. As such, you can not determine volts from watts without knowing something else, such as amperes (coulombs per second) or ohms.
The conversion of Amps to Watts is governed by the equation Watts = Amps x Volts. For example 1 amp * 110 volts = 110 watts
You have two unknowns for this equation, 1) the voltage which you want to find, and 2) the amperage. You must know the amperage to find your answer. In household current the voltage is 110-120. However, if you use a car battery, the voltage is 12.
You could have the amperage and then use the equation above.
4 amps: 500watts = 4amps X ? volts. 500 watts/4amps = 125volts (close to household current)
42 amps: 500watts = 42amps X ?? volts. 500watts/42amps = 11.9volts prox. (close to a car battery)
1 amp: 500watts = 1amp X ??? volts. 500watts/1amp = 500volts (about like a large electric eel--300 to 800 volts)
The characteristic curve of a diode?
A diode characteristic curve is a curve that describes the characteristic of diode and it is normally based on experiment data.
The curve itself has two distinctly separate parts.One part lies in the first quadrant and it stands for the forward-biased situtation.It reflets the barrier voltage(meaning the smallest amount of voltage that can turn on the diode).For Germannium diode,the barrier voltage is 0.3V while silicon diode is 0.7V,but the real value differs according to the temperature and current flows through the diode.The other part lies in the third quadrant which indicates the reverse-biased situation,from which you can find out the leakage current(the current flow through before Breakdown Point).
Typcially, a diode characteristic curve varies from diode to diode.But theoretically speaking,we regard them as the same.
What is V-I characteristics of zener diode?
Work in reverse bias.(breakdown at a particular voltage to keep the volt. constant so used as voltage regulator)
same as diode when forward biased.
What is the emitter bypass capacitor?
The capacitor helps to keep the quiesent point fixed. During its operation it bypasses the ac component. If the ac also flows through this emitter link then as we know by parameter equations emitter current and ce voltage changes hence varying q point.
What is Full load current in transformer?
The no-load current of a transformer is the current which is drawn from the source at rated voltage and frequency even when no actual load current is being supplied.
The no-load current is what must be drawn to overcome the inherent and unavoidable losses of the transformer's components. Those losses comprise the primary circuit's resistance (known either as the "copper losses" or as the "resistance losses") and the transformer's magnetic reluctance (known either as the "iron losses" or as the "magnetic losses").
Reluctance is the techical description given to the energy necessary to excite the magnetic circuit and overcome its hysteresis, the effects of eddy currents, etc.
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